Pump Diaphragm Composite Core Fatigue Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing diaphragms in air-driven double diaphragm pumps face challenges in withstanding substantial oscillating stresses and fatigue over a large number of cycles, particularly in larger sizes where robustness is needed to maintain operational integrity.
Innovation Solution
A diaphragm assembly featuring an inflexible core with a radially extending plate and a unitary diaphragm body made of thermoplastic elastomer, integrated with a thermoplastic coating and connective tendons, providing structural support and integrity through an annular ring portion and a mounting surface with a threaded hole for additional stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If molded diaphragms with composite structures are used, then small size diaphragms can withstand cycling forces, but large size diaphragms lack robustness to maintain operational integrity
Solution Approach 1:
The diaphragm employs a composite structure combining a rigid central piston (made of rigid material with inflexible characteristics) and a flexible peripheral portion (made of elastomeric material). This composite construction allows the central region to provide structural robustness for larger diaphragms while the peripheral portion maintains flexibility for pumping operations, resolving the contradiction between size and robustness.
2Reliability
If the diaphragm is made flexible for pumping operation, then it can pump materials, but it cannot withstand substantial oscillating stresses over vast numbers of cycles
Solution Approach 1:
The diaphragm is segmented into distinct functional zones: a rigid central piston region that withstands oscillating stresses and maintains structural integrity over vast cycles, and a flexible peripheral portion that performs the pumping function. This segmentation allows each zone to optimize its properties for its specific function, resolving the contradiction between flexibility and cycle life.
Solution Approach 2:
Different regions of the diaphragm have different mechanical properties tailored to their functions. The central piston region has rigid, stable composition for stress resistance, while the peripheral portion has flexible elastomeric composition for pumping. This local differentiation resolves the contradiction between overall flexibility and localized stress resistance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The diaphragm assembly effectively sustains long cyclical operation and substantial oscillating stresses, enhancing the robustness and longevity of the diaphragm, enabling it to handle vast numbers of cycles without fatigue failure.
Implementation Method 1
a thermoplastic coating thermally bonded to the inflexible core
Implementation Method 2
a unitary diaphragm body molded with the inflexible core in situ
Data Source
AI summary
A diaphragm assembly for a fluid driven diaphragm pump includes a piston having an inflexible core. This core includes a hub with a plate extending radially from about the periphery of the hub. The piston further includes a unitary diaphragm body molded with the inflexible core in situ. The unitary diaphragm body has a plurality of connective tendons extending through the plate. A thermoplastic coating extends about the inflexible core between the core and the molded unitary diaphragm body having a thermally miscible surface with the thermoplastic coating. An inflexible backing plate extends in juxtaposition with the diaphragm.